Portion of an article of footwear



FIG. 1 is a bottom perspective view of a portion of an article of footwear showing my new design;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a right side elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a front elevational view thereof; and,

FIG. 6 is a rear elevational view thereof.

The broken line illustration is not part of the design sought to be patented.

The broken-line rectangle in FIGS. 1 & 2 forms the boundary of the design. The broken lines and the area within, form no part of the claim. 

The ornamental design for a portion of an article of footwear, as shown and described. 